入门实践丨如何在K3s上部署Web应用程序

git clone https://github.com/benjamintanweihao/Flask-MongoDB-K3s-KNative-TodoApp

% cd Flask-MongoDB-K3s-KNative-TodoApp% tree

├── app.py├── requirements.txt├── static│   ├── assets│   │   ├── style.css│   │   ├── twemoji.js│   │   └── twemoji.min.js└── templates    ├── index.html    └── update.html

mongodb_host = os.environ.get('MONGO_HOST', 'localhost')mongodb_port = int(os.environ.get('MONGO_PORT', '27017'))client = MongoClient(mongodb_host, mongodb_port)db = client.camp2016todos = db.todo 
app = Flask(__name__)title = "TODO with Flask"
@app.route("/list")def lists ():    #Display the all Tasks    todos_l = todos.find()    a1="active"    return render_template('index.html',a1=a1,todos=todos_l,t=title,h=heading)
if __name__ == "__main__":    env = os.environ.get('APP_ENV', 'development')    port = int(os.environ.get('PORT', 5000))    debug = False if env == 'production' else True    app.run(host='0.0.0.0', port=port, debug=debug)

FROM alpine:3.7COPY . /appWORKDIR /app
RUN apk add --no-cache bash git nginx uwsgi uwsgi-python py2-pip \    && pip2 install --upgrade pip \    && pip2 install -r requirements.txt \    && rm -rf /var/cache/apk/*
EXPOSE 5000ENTRYPOINT ["python"]

% docker build -t <yourusername>/todo-app .

# ...Successfully built c650af8b7942Successfully tagged benjamintanweihao/todo-app:latest

services:  flaskapp:    build: .    image: benjamintanweihao/todo-app:latest    ports:      - 5000:5000    container_name: flask-app    environment:      - MONGO_HOST=mongo      - MONGO_PORT=27017    networks:      - todo-net    depends_on:      - mongo    volumes:      - .:/app # <---   mongo:    image: mvertes/alpine-mongo    ports:      - 27017:27017    networks:      - todo-net
networks:  todo-net:    driver: bridge

COPY . /app

docker-compose up

Creating network "flask-mongodb-k3s-knative-todoapp_my-net" with driver "bridge"Creating flask-mongodb-k3s-knative-todoapp_mongo_1 ... doneCreating flask-app                                 ... doneAttaching to flask-mongodb-k3s-knative-todoapp_mongo_1, flask-app# ... more output truncatedflask-app   |  * Serving Flask app "app" (lazy loading)flask-app   |  * Environment: productionflask-app   |    WARNING: Do not use the development server in a production environment.flask-app   |    Use a production WSGI server instead.flask-app   |  * Debug mode: onflask-app   |  * Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)flask-app   |  * Restarting with statmongo_1     | 2021-05-15T15:41:37.993+0000 I NETWORK  [listener] connection accepted from 172.23.0.1:48844 #2 (2 connections now open)mongo_1     | 2021-05-15T15:41:37.993+0000 I NETWORK  [conn2] received client metadata from 172.23.0.1:48844 conn2: { driver: { name: "PyMongo", version: "3.11.4" }, os: { type: "Linux", name: "", architecture: "x86_64", version: "5.8.0-53-generic" }, platform: "CPython 2.7.15.final.0" }flask-app   |  * Debugger is active!flask-app   |  * Debugger PIN: 183-021-098

index d322672..1c447ba 100644--- a/app.py+++ b/app.py-heading = "tOdO Reminder"+heading = "TODO Reminder!!!!!"

docker-compose down

% curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC="server --no-deploy=traefik"  sh -s -

[INFO]  Finding release for channel stable[INFO]  Using v1.20.6+k3s1 as release[INFO]  Downloading hash https://github.com/k3s-io/k3s/releases/download/v1.20.6+k3s1/sha256sum-amd64.txt# truncated ...[INFO]  systemd: Starting k3s

% kubectl get noNAME      STATUS   ROLES                  AGE     VERSIONartemis   Ready    control-plane,master   2m53s   v1.20.6+k3s1

helm install mongodb-release bitnami/mongodb --set architecture=standalone --set auth.enabled=false

** Please be patient while the chart is being deployed **
MongoDB(R) can be accessed on the following DNS name(s) and ports from within your cluster:
    mongodb-release.default.svc.cluster.local
To connect to your database, create a MongoDB(R) client container:
    kubectl run --namespace default mongodb-release-client --rm --tty -i --restart='Never' --env="MONGODB_ROOT_PASSWORD=$MONGODB_ROOT_PASSWORD" --image docker.io/bitnami/mongodb:4.4.6-debian-10-r0 --command -- bash
Then, run the following command:    mongo admin --host "mongodb-release"
To connect to your database from outside the cluster execute the following commands:
    kubectl port-forward --namespace default svc/mongodb-release 27017:27017 &    mongo --host 127.0.0.1

kubectl apply -f https://github.com/knative/serving/releases/download/v0.22.0/serving-crds.yamlkubectl apply -f https://github.com/knative/serving/releases/download/v0.22.0/serving-core.yamlkubectl apply -f https://github.com/knative/net-istio/releases/download/v0.22.0/istio.yamlkubectl apply -f https://github.com/knative/net-istio/releases/download/v0.22.0/net-istio.yaml

kubectl get pods --namespace knative-serving -wNAME                                READY   STATUS    RESTARTS   AGEcontroller-57956677cf-2rqqd         1/1     Running   0          3m39swebhook-ff79fddb7-mkcrv             1/1     Running   0          3m39sautoscaler-75895c6c95-2vv5b         1/1     Running   0          3m39sactivator-799bbf59dc-t6v8k          1/1     Running   0          3m39sistio-webhook-5f876d5c85-2hnvc      1/1     Running   0          44snetworking-istio-6bbc6b9664-shtd2   1/1     Running   0          44s

kubectl apply -f https://storage.googleapis.com/knative-nightly/serving/latest/serving-default-domain.yaml

# other parts truncated     spec:    serviceAccountName: controller    containers:        - name: default-doma          image: ko://knative.dev/serving/cmd/default-domain          args: ["-magic-dns=sslip.io"]

% kn service create helloworld-python --image=docker.io/benjamintanweihao/helloworld-python --env TARGET="Python Sample v1"

Creating service 'helloworld-python' in namespace 'default':
  0.037s The Route is still working to reflect the latest desired specification.  0.099s Configuration "helloworld-python" is waiting for a Revision to become ready. 29.277s ... 29.314s Ingress has not yet been reconciled. 29.446s Waiting for load balancer to be ready 29.605s Ready to serve.
Service 'helloworld-python' created to latest revision 'helloworld-python-00001' is available at URL:http://helloworld-python.default.192.168.86.26.sslip.io

% kn service  list -A

% kubectl get ksvc -A

kn service delete helloworld-python # or kubectl delete ksvc helloworld-python

% docker push {username}/todo-app:latest

kn service create todo-app --image=docker.io/{username}/todo-app --env MONGO_HOST="mongodb-release.default.svc.cluster.local" 

Creating service 'todo-app' in namespace 'default':
  0.022s The Route is still working to reflect the latest desired specification.  0.085s Configuration "todo-app" is waiting for a Revision to become ready.  4.586s ...  4.608s Ingress has not yet been reconciled.  4.675s Waiting for load balancer to be ready  4.974s Ready to serve.
Service 'todo-app' created to latest revision 'todo-app-00001' is available at URL:http://todo-app.default.192.168.86.26.sslip.io